59 



Table of Quebec Species of the Genus Plusia. 



I. — Having white or metallic markings in the middle of the fore-wings. 



A. Having y-like markings in the middle of the fore- wings. 



a. Having two golden marks as if the tail were cut off from the y. 



PuTNAMi, which has a golden apical streak. 

 BiMACULATA, which has a brown apical streak. 



b. Having the y complete. 



1. Tarsi of front legs banded brown and white. 



Falcifera, which has no knob at the end of the y. 

 Precationis, which has the tail of the y knobbed. 



2. Tarsi of the front legs plain. 



Simplex. 



B. Having markings of other forms in the middle of the fore- wings. 



a. Like K U-Aureum. 



b. Undulating, like a small snake. Ampla. 



c. Like the figure 3 lying on its back. ViRlDisiGNATA. 



d. Plume-like. Mortuorum. 



e. Like a small v followed by a dot or annulet. 



1. Having pink spots on the wings. Thyatiroides. 



2. Having tawny wings. Mappa. 



3. Having greyish-brown wings. Brassic^. 



IL — Having no metallic markings in the middle of the fore-wings. 



A. Having the wings glossy-green. Balluca. 



B. Having the wings glossy -brown. 



CL Dark brown, ^rea. 



6. Light-brown. ^.REoiDES. 



ORIGIN AND PERPETUATION OF ARCTIC FORMS. 



BY J. ALSTON MOFFAT. 



The subject of Arctic Forms is one of special interest in biology, and the 

 frequent reference to it in natural history literature, keeps it constantly before 

 the reader, and has made the theories concerning the origin and preservation of 

 such forms well known, whilst to us as entomologists, it is of the very first im- 

 portance in our etiorts to obtain correct knowledge concerning the geographical 

 distribution of insects. Grant Allen says . — 



"On or near the summit of Mount Washington, a small community of butter- 

 flies belonging to an old glacial and Arctic species still lingers over a small area, 

 where it has held its own for eighty thousand years that have elapsed since the 

 termination of the great ice age. This same butterfly is found in two other 

 localities on this continent ; Long's Peak, Colorado, is eighteen hundred miles 

 distant; Hopedale, Labrador, is probably a thousand miles away ; in the intervening 

 districts there are no insects of the same species. Hence we must conclude, that 

 a few butterflies left behind in the retreating main-guard of their race, on that 

 one New Hampshire peak, have gone on for thousands and thousands of years, 

 producing eggs, and growing from caterpillars into mature insects, without once 

 affecting a cross with their congeners." 



